In 2000, the NCRR awarded the MIT Francis Bitter Magnet Laboratory a Phase 1 program of a 3-phase project to complete a 1-GHz NMR magnet comprised of a low- temperature superconducting (LTS) magnet and a high-temperature superconducting (HTS) insert. With the successful completion of a 700-MHz LTS/HTS magneta 600- MHz LTS magnet and a 100-MHz HTS insertand the Phase 2 program about to end, we are poised to embark on Phase 3, first Phase 3A, to be followed by Phase 3B with an upgraded goal of completing a 1.3 GHz LTS/HTS NMR magnet (LH1.3G). The two most compelling arguments for extending NMR to higher frequencies are better spectral resolution and sensitivity. The specific aims of the Phase 3A program are to: 1) complete a 600-MHz all-HTS insert (H600) and operate it in the bore of a 500 MHz LTS NMR magnet (L500), already available at FBML, not only to generate a 1.1 GHz field (25.84 T) but also to subject H600 to a magnetic field and mechanical stresses sufficient enough to demonstrate its successful performance in the bore of a 700-MHz LTS magnet (L700) in Phase 3B; 2) measure the harmonic errors generated by screening- current fields of H600 itself and in combination with L500; and 3) develop techniques, to be applied to LH1.3G, to ameliorate the harmonic errors of H600. The specific aims of the Phase 3B program are to: 1) complete a high-resolution 1.3 GHz LTS/HTS NMR magnet, achieved with a combination of H600 completed in Phase 3A and a new L700; and 2) install the LH1.3G as a new powerful tool for NMR research in the MIT/Harvard Center for Magnetic Resonance at FBML. The significance of the Phase 3A program is its direct and indispensable benefit to LH1.3G, in which H600, together with L700, will constitute two key magnet components.Significant goals in Phase 3A, all of which are essential elements required to complete a high-resolution 1.3 GHz LTS/HTS NMR magnet in Phase 3B: 1) completion of a 600 MHz HTS (H600) insert capable of operating in a background field of an LTS 700-MHz NMR magnet (L700); 2) completion of a 1.1-GHz NMR magnet comprising the H600 and an 500-MHz LTS NMR magnet; 3) the magnetic characterization of H600. The two most compelling arguments for extending NMR to higher field are spectral resolution and sensitivity.